Oh dear, sorry to hear about the kerazee FIL. They're difficult enough to deal with at the best of times, without adding insanity into the mix. I must admit, I'd love to know what he did. Hope he's not getting to you and your hubbie too much!!
sorry for your troubles missus!
you should have done this years ago
Call his bluff!! and if it bothers you let on the DH that it does and tell your hubbie to relax that you both need to live your lives and not be so influenced by his threats - cryptic enough for ya